codewar.rb

def find_missing_number(sequence) 
  # sort the numbers in ascending numerical order
  # non-string values will be at the beginning
  # will be the value 0.  This doesn't modify
  # the actual array (convert it to an integer)
  # it just uses this to map to the array.
  numbers = sequence.split.sort do |x, y|
    x.to_i <=> y.to_i
  end
  
  prev = 0
  numbers.each do |number|
    puts number.inspect
    if number.to_i.to_s != number
      return 1
    end
    if number.to_i != prev + 1
      return prev + 1
    end
    
    prev = prev + 1
  end
  return 0
end